1. Field of the Invention
The invention relates to information security, and more particularly, to systems and methods for improving the security of information transactions over networks.
2. Description of the Related Art
The internet has become an important medium for information services and electronic commerce. As the internet has been commercialized, organizations initially established their presence in cyberspace by making information (typically static, non-sensitive promotional information) available on resources well removed from the operational infrastructure of the organization. Security issues were often addressed by isolating publicly accessible resources (e.g., web servers) from more sensitive assets using firewall techniques. As long as the publicly accessible information and resources were relatively non-sensitive and user interactions with such information and resources was not mission critical, relatively simple firewall techniques were adequate. Though information and resources outside the firewall were at risk, the risk could generally be limited to non-proprietary information that was easily replaceable if compromised. Proprietary information and systems critical to day-to-day operations were sheltered behind the firewall and information flows across the firewall were filtered to exclude all but the comparatively non-threatening services such as electronic mail.
However, as the internet has become pervasive, and as the sophistication of tools and techniques has increased, several aspects of the security environment have changed dramatically. First, businesses have recognized the power of information transactions that more tightly couple to operational data systems, such as order processing, inventory, payment systems, etc. Such transactions include electronic commerce with direct purchasers or consumers (e.g., browsing, selecting and purchasing of books by members of the public from an on-line bookseller) as well as supply chain and/or business partner interactions (e.g., automated just-in-time inventory management, customer-specific pricing, availability and order status information, etc.). In short, commercially relevant transactions increasingly require information flows to and from secure operational systems. Second, even information-only services are increasingly mission-critical to their providers. Corporate image can be adversely affected by unavailability of, or degradation access to, otherwise non-sensitive information such as customer support information, product upgrades, or marketing and product information. Because many businesses rely heavily on such facilities, denial of service attacks represent an increasing threat.
In information security environments, authentication facilities are typically designed to establish to a desired degree of certainty that a particular transaction is performed on behalf of a particular principal. Similarly, authorization facilities are designed to enforce security policies limiting access on behalf of an authenticated principal to a particular subset of information resources. Unfortunately, despite well designed authentication and authorization facilities, information security policies and systems designed to implement such policies may be subverted by malformed requests or even well formed requests that attempt an end run around a security policy. For example, malformed requests may be employed to access secure systems by exploiting buffer overflow or similar types of security holes. In addition, malformed requests may be employed in denial of service type and other malicious attacks to crash or load down a server or information resource. Another threat involves the passing of directives (e.g., SQL statements, scripts, etc.) into an otherwise secure environment without validation and directly to an interpreter or other execution environment (e.g., an SQL engine, shell, etc.). Response messages may also be employed in ways that subvert a security policy, although such threats usually imply compromised applications or directives passed into the secure environment.
Improved systems and techniques are needed to better manage information flows across security boundaries such as those provided by a firewall (or firewalls). Otherwise, the increasingly need for access to operational systems and data threatens to compromise the security of such system and data. Alternatively, security concerns will severely limit the viability of advanced electronic commerce techniques.